The film will tell the story of the Hollywood actress-turned-princess' influence on the Principality of Monaco, as well as how she and her husband decided to address a national tax crisis -- together.

Princess Grace and Prince RainierCredit: Newscom

Frank Langella is also reportedly in talks to play the priest who introduced Kelly and Prince Ranier, while actress Paz Vega will appear as famed opera singer Maria Callas, who dated Aristotle Onassis and was one of Kelly's closest friends.